BIP352: Add support for Pay-to-Anchor (P2A) in get_pubkey_from_input #1707

1. 
   Gudnessuche commented at 4:27 pm on November 30, 2024: contributor

   This commit adds a conditional statement to the get_pubkey_from_input function to handle Pay-to-Anchor (P2A) address types. The function now checks if the previous output is a P2A address type and extracts the public key from the anchor_script. This update ensures compatibility with the Bitcoin protocol for P2A address types and enhances the function’s versatility in processing various address types.
2. Add support for Pay-to-Anchor (P2A) address type in get_pubkey_from_input function

   This commit adds a conditional statement to the get_pubkey_from_input function to handle Pay-to-Anchor (P2A) address types. The function now checks if the previous output is a P2A address type and extracts the public key from the anchor_script. This update ensures compatibility with the Bitcoin protocol for P2A address types and enhances the function's versatility in processing various address types.

   b999ac2d53
3. jonatack renamed this:
   Add support for Pay-to-Anchor (P2A) address type in get_pubkey_from_i…
   BIP352: Add support for Pay-to-Anchor (P2A) in get_pubkey_from_input
   on Dec 5, 2024
4. jonatack added the label Proposed BIP modification on Dec 5, 2024
5. 
   Gudnessuche commented at 9:25 am on December 5, 2024: contributor

   Thank you so much @jonatack for the appropriate name change.

   When merge?

6. murchandamus added the label Pending acceptance on Dec 6, 2024
7. 
   murchandamus commented at 6:33 pm on December 6, 2024: contributor

   This needs review and sign-off from the BIP’s authors.

   cc: @josibake, @RubenSomsen

8. in bip-0352/reference.py:82 in b999ac2d53

   77@@ -78,6 +78,11 @@ def get_pubkey_from_input(vin: VinInfo) -> ECPubKey:
   78             pubkey = ECPubKey().set(vin.prevout[2:])
   79             if (pubkey.valid) & (pubkey.compressed):
   80                 return pubkey
   81+    if is_p2a(vin.prevout): 
   82+        anchor_script = vin.scriptSig[1:] 
   

   ---

   ---

   

   theStack commented at 1:45 pm on December 9, 2024:

   scriptSig for segwit spends is always empty by consensus rules, so this line doesn’t make sense (see also https://bitcoin.stackexchange.com/questions/124615/is-the-scriptsig-spending-an-paytoanchor-output-expected-to-always-be-empty).

   ---

   

   Gudnessuche commented at 3:06 pm on December 9, 2024:

   Hmmm interesting, so it’s best to close this PR then?
9. 
   theStack commented at 1:46 pm on December 9, 2024: contributor

   The function now checks if the previous output is a P2A address type and extracts the public key from the anchor_script.

   Note that the P2A output type intentionally doesn’t involve keys, so there is nothing we could extract. I think there is no gain in handling this case explicitly, as we’d end up in the “nothing matched” (return ECPubKey()) case anyway, so it would be a no-op.

Contributors
Gudnessuche murchandamus theStack

Labels
Proposed BIP modification Pending acceptance